Artificial limb construction



June 17, 1947. B. HORN ARTIFICIAL LIMB CONSTRUCTION Filed Sept. 25, 19464 eznard for@ Patented June 17, 1947 UNITED STATES RTENT OFFICE ARTIFICIAL VHMB CONSTRUCTION Bernard Horn, Chicago, Ill.

Application September 23, 1946, Serial'No. 698,743-

lk Claims.

This invention relates to an artical limb construction and particularly to anartificial hand. It is essential that an artificial4 hand be light and strong and be susceptible to manipulation. While many artificial hands purport to fulfill these requirements, their construction has been characterized by complexity resulting in substantial weight. It is desirable that an artificial hand be mechanically simple, simulate a human hand and be capable of being maintained in a clean and sanitary condition. The invention hereinafter described fulfills these requirements to a high degree.

The invention in general provides a construction utilizing ball and socket joints. The ball and socket joints are preferably so designed that the friction between the ball and socket may be adjusted to any desired value. In the practical use of such a hand, the ball and sockets are adjustedI so' that considerable friction is provided. Thus, the hand and ngers may be preadjusted to any desired position and will maintain themselves in position.

A construction embodying the present invenh tion is light and strong and may have areadily removable glove to simulate the flesh and muscles of a human hand. The resulting hand may not only be used as a prostheticy appliance by amputees but may also be used in manikins and display iigures.

In order to fully understand the invention, reference will now be made to the drawing wherei-n Figure l is a view partly in section of an artificial hand and wrist embodying the present invention. Figure 2 is a sectional detail upon line 2-2 of Figure 1. upon line 3--3 of Figure l'.

A hand, generally indicated by numeral Ill is supported by ball II within socket construction l2 to forma carpus or wrist. Ball' I'I may be of plastic, such as Bakelite, or of. metal as aluminum, stainless steel or any other suitable material. Ball II is gripped by two cupped members I3 and Ill forming socket I2, these two cupped members being carried at the ends of links I5 and I6. Links I5 and I6 may extend as far back as desired' and, if necessary, may go to an elbow construction generally similar to the wrist structure. As shown here, stump I'I supports links I5 and I6. Links I5 and I6 are preferably integral with cupped members I3 and Il and are formed of a suitable material having substantial strength and elasticity, such as steel as an example. They may have any desired transverse cross-section but may be rounded like the Figure 3 is a sectional detail' phalangeal links described later. Immediately adjacent` the ball and socket construction, links I5' and I5` are clamped. togetherl by any suitable means such as bolt lilV threadedly engaging link portion i6. Link portion I5 is suitably counter'- sunk: to accommodate the bolt head, it being understood thatV boltv i8' turns loosely in link porftion I5. Thus, bolt I8' providesa viselike action on links I'- and IIi` and controls the gripping 'action of the joint.

It is understood that cup portions I3 andv Il! cover as much of the surface` of balll H asnecessary. However, cup. portions IB'and i4 haveopen region 2li within which connecting portion 2li extends to ball Il. Region 2li is great enough soA tz'iat a suitableV range of adjustment of ball I'I with. respect to socket I2vv is provided. As shown here, connecting portionv 2i has a Width somewhat greaterV than the separation between opposing edges of cup members I3- and HI. Thus, adjustment of ball Il with respect to socket I2 is possible in all` planes to provide universal action.

While the balll andk socket are shown as having smooth surfaces, it is possible to roughen one. or both of the cooperating surfaces to increase the friction. It is also possible to make the ball and socket of dissimilar materials.. Thus, ball ll may be of brass, and socket i12 may be of steel. Connecting portion 2l is rigidly fastened toA ball II in any suitable manner andv extends away therefrom to metacarpal region 23. Metaca-rpal portion 23 has undercut part 24 cooperating with piece 25 to form socket 26. The socket forming members are maintained in position by bolt 2l as in socket I2. Socket 2 cooperates with ball- 28 carried bymember 29' simulating the proximal phala-ngeal bone of the rst nger. Member 28 may bciiat or cylindrical and carries ball 3@ at the end thereof corresponding to the middle phalangeal joint. Ball 30 is engaged by links 3-I and 32 forming socket 33 at ball 30 and socketv 34 at the distal joint of the rst finger. Links 3i and 32 are short enough in length so that one bolt 35 may be used to control the gripping action of the two sockets. t is understood that bolt 35- cooperates with. the twolinks in a manner similar to bolt i8. Instead of one bolt 3.5, if desired, two separate tension adjusting means may be provided adjacent socketsv 33 andy 34. Cooperating with socket 35 is ball :It4 carried by distal member 31.

Metacarpal portion 23 is shaped toprovide links and di forming part of the skeleton structurefrom which the second and iiith lingers respectively extend. Cooperating with link 40 is link 42 rigidly attached at base 43 to neighboring link 44 to form a generally U-shaped piece. Inasmuch as the various links are made of elastic material, it will be evident that some iiexibility between two links will be possible.

Cooperating with link 44 is link 45 joined at base 45 with neighboring link 41. Link 41 cooperates with link 48 joined at base 49 to link 50. Links 40 and 42 have bolt 52 for adjusting the tension between them. Similarly, bolts 53, 54 and 55 are provided for the remaining sets of links.

Links 4l) and 42 together cooperate to form socket 6U. Links 44 and 45 provide socket 6l. Links 4'! and 48 provide socket 62, While links 50 and 4l cooperate to provide socket 63. Sockets 60 to 63 inclusive cooperate with balls 65 to 5S inclusive respectively to form proximal phalangeal or knuckle joints. Balls 60 to 68 are carried upon small extensions from rods 59 to 72 inclusive. These rods may either be flat or cylindrical and carry balls 14 to 'Il inclusive upon suitable extensions at the upper ends thereof. The lengths of rods 59 to 12 inclusive are such as to simulate the normal phalangeal bones between the proximal and middle phalangeal joints.

Cooperating with balls 14 to Ti inclusive are sockets 13 to 8| inclusive. The sockets are formed from links in the same manner as described in connection with the first nger or thumb. Thus, the second or index nger, for example, has links 83 and 84 cooperating with bolt 85 for controlling the ball and socket action. Links 83 and B4 have socket 86 retaining ball 87 carrying member S8 to form a jointed or articulated distal phalangeal portion. The remaining ngers are similarly constructed. It is clear from the construction of the various joints that the clearances between the socket and ball members are such as to control the plane or planes in which articulation is possible. Thus, the middle phalangeal joints and distal phalangeal joints should be constructed so that desired articulation is possible. While the phalangeal articulation in a human hand is limited to a plane generally perpendicular to the palm, an articial hand may be made to have a greater degree of freedom.

Those joints which permit bending in one direction only from a straight line position may be constructed generally along the lines as shown in Figure 3, for example. Thus, the socket formball movement. It will be noted, however, thatV opposing edges 90 and 9| extend part way through the socket with edges 92 and 93 extending the remaining portion. Edges 92 and S3 are spaced close enough to prevent the ball retaining portion from moving between these edges. Thus, as shown, the tip of the fourth nger can only be bent upwardly from a straight position but cannot be bent downwardly or backwardly from a straight position.

The knuckle or proximal phalangeal joints are preferably constructed in a manner generally similar to the wrist joint so that a limited amount of universal articulation is provided. The angular extent of joint action from a straight position need not necessarily be the same in all directions. Thus, the knuckle joints should have substantial freedom to bend in such a manner as to bring the ngers toward the palm. Bending backward is not necessary or desirable. Some slight bending sideways may be provided. Thus,

4 applying the construction of Figure 3 to a knuckle joint, the spacing between opposed edges 90 and 9| may be enlarged somewhat or evenk tapered to provide some side articulation,

. The entire hand may be covered with a suitable rubber or plastic material 95 to simulate the appearance of a normal hand, or, if desired, to simulate a, glove. This plastic covering is preferably removable to permit adjustment of the various joints. By suitable design of the plastic covering, the Various pads and wrinkles in a normal hand and in normal fingers may be duplicated. By making such plastic material somewhat iiexible, the same covering may be used for various sizes of hands. Padding may be inserted to ll out various spots. The entire cover may be fastened to the stump by snaps 95.

It is understood that the balls may bemade adjustable and socket members xed as far as grip adjustment of the joints are concerned.

What is claimed is:

1. An artificial hand comprising a palm portion, wrist portion, thumb and four nngers, said palm portion consisting of a solid member having one part extending Atoward the wrist, ball and socket means in said wrist to provide a joint, said one part of the palm being rigidly attached to one portion of said joint, jointed portions form-i ing a thumb but attached to another portionV of said palm and jointed portions being attached to a third portion of a palm for fingers, finger portions immediately adjacent to the palm consist-.- ing of two spaced links forming part of the second and fth ngers respectively, three generally U shaped links disposed between said two spaced links, means for coupling the links in pairs to form four pairs of links for the second to fth ngers inclusive, each pair of links having the free ends shaped to denne a knuckle socket, rods having a ball at each end, each linger having one rod with a ball engaged by said knuckler socket, a pair of links for each nger beyond the corresponding rod and corresponding tothe free half of each finger, each link being shaped to provide a socket at each end thereof, means for coupling said links together to provide a, gripping action at each ball and socket joint, and a ball and finger tip extension for the outermostsocket for all ngers.

2. In an articial limb, an articulated construction comprising a rigid link carrying a ball at least at one end thereof, an elongatedmember.

in general alignment with said link, said elongated member having two cooperating cupped portions enclosing said ball to form a ball and socket joint, and means for urging said two cupped portions toward each other to grip the ball.

3; In an artificial hand, an articulated iinger comprising a rigid link having a ball at leastat one end thereof, a pair of rigid members having cupped portions at the ends thereof, two cooperating cupped portions at one end engaging said ball, a, third link carrying at least one ball vat its end, saidV third link having the ball between the cooperating cupped portions. at the other end,` and bolt means for tightening said two members toward each other to causethe cupped ends to grip the balls. Y

5 6 parts embracing the balls to form ball and socket E .NT joints for the distal and middle phalangedl joints UNHED STAT s PATE S respectively, means for retaining the two mem- Number Name Date bers in rigid relation to form said phalangeai link 1,484,913 Surry Feb. 26, 192: and grip the balls and a ball and Socket mount.- 5 370,774 Fuller Oct. 4, 188( ing means functioning as a, knuckle joint. 1,630,022 Hodgson Aug. 7, 1928 BERNARD HORN' FOREIGN PATENTS REFERENCES CITED Number Country Date The following references are of record in the 10 76,240 Aust/na Apr 25: 1929 le of this patent: 

